In this paper, it is shown that Lectures Five, Six, and Seven of William James's Pragmatism contain the following three interesting, but puzzling and often misunderstood, theses on reality: conceptual scheme pluralism, the thesis of the mutation of reality, and a humanist view of reality. Taken together, I consider these ”James's pragmatic notion of reality.” It is argued that James can be better interpreted as explaining and defending these three theses from an epistemological perspective, within a framework based on both his holistic model of belief revision and his notion of ”three-fold realities.” Finally, I investigate whether the objection that there are insufficient objective regulations on belief successfully challenges his model of belief revision and these three theses on reality.